Terminal bank and method of constructing it



Nov. 29, 1927.

E. W. GENT TERMINAL BANK AND METHOD OF CONSTRUCTING IT Filed Feb. 1924Patented Nov. 29, 1927.

UNITED 1 STAT-ES PATENT OFFICE;

EDGAR w. GENT, or MORRISTOWN, NEW JERSEY, AssIeNon To WEsTERN ELEc nIcCOMPANY, INCORPORATED, 015 NEW YORK, N. Y., ACOBPOBATIQN on NEW YORK.

TERMINAL A KnNnMETrIoD or CONSTRUCTING IT.

Application filed February ratus and more particularly to terminal banksfor telephone switches.

Terminal banks of the panel type are well known in the art'andhaveheretofore usually been made by superimposing alternate layers ofconducting elements and insulation and compacting the structure bypressure. Banks made in this manner, particularly where they are ofconsiderable height, have been found to vary' somewhat in the verticaldistance between terminals, due to uneven compression of the insulation.Considerable labor has therefore been'required to properly space theterminals in the completedbank.

It is an object of the present invention to provide an improved terminalbank and method of forming the same.

' A feature of the inventlon is theformation of a bank of spacedconducting elements held in. place by means of sheets of insulationapplied parallel to the surface of the bank. r r

A further feature of the invention lies in the provision of slots andcorrugations in said sheets of insulation for positioning the conductorsand for strengtheningthe bank.

A further feature of the invention lies in forming the bank of aplurality of semiv 1 cured sheets of insulation and applying heat andpressure to cure the insulation and form the several sheets into ahomogeneous structure.

will be more clearly understood from a consideration of the followingdescrlption taken in connection with the drawings and the InthedrawingszI V Fig. 1 shows a portlon of one type of'terminal bank formedinaccordance with the present invention. I i r i Fig. 2 shows a portion ofthe same typeof terminal bank adapted for use. in a coordinate typeswitch.

Fig. 3 shows a cross-section ofthe elements forming a bank. J a

Fig. 4 shows a cross section of the elements of Fig. 3 taken along thelinek4.

Fig. 5 is a modified form of bank also These and other features of theinvention 7,1924. Serial No. 691,197.

made in accordance with 'the'present invenif tion. 4 Considering Figs.1, 3 and 4, the sheets of lnsulation 1, 2, 3, and 4 may be of anysuitable material which is formed in sheets and which when so'formedwill have sufficient rigidity. They'are preferably of the type formedwhen canvas of fiber is impregnated by a'phenol formaldehyde resinandknown commercially by Various trade names such as celeronl. These sheetsare marketedina a terminal bank, slots 5 and 6 are cut in the sheets andthe sheets corrugated to theforin shown in Fig. 3, or the sheets may becorrugated first and slottedlater. It is to he noted that the slots 5are somewhat deeper than the slots 6 for the purpose of centering thecontact wires in the assembly. The wires 7, 8 are then stretched in twoparallel planes in any suitable manner, the slotted sheets of insulationarranged as shown in Figs. 3 and 4 and brought together so that thewires 7 and 8 are engaged in the slots v5 and 6. and thecorrugations 1nthe varlous sheets engage one another. The whole is then submitted toheat andpressure whereby the semi-cured sheets of insulation are curedand formed into one laminated sheet. The bank so formed is strengthenedhorizontally by the wires forming the contacts and vertically by thecorrugations in; the insulation. The surface presented .by the curedinsulation is smooth and the method of forming the bank transverselyholds the contactwiresjin place adapted for use with the type of switchdisclosed and claimed in U; S. Patent 1375230 granted April 19, 1921, toJ. N. Reynolds or with thatdisclosed and claimed in U. S;

. brushes 2 5, 26 and 27. As the terminal "bank is double faced two setsof switches may;v

Patent 1,12%642 granted December 29, 1914.; '9

be used therewith the brushes of one engaging the wires 8 on one face ofthe bank and of the other engaging the wires 7 on the opposite faceofthe bank.

The method in which this terminal bank may be adapted for use with thecoordinate switch, such as is disclosed and claimed in the patent to J.N. Reynolds, No. 1,5 07,1a0', granted September 2, 1924-, is shown InFig. 2. The bank is formed with a single row of conductors arranged ingroups and two sheets of insulation. Perforations 9 are formed in thesheets 10 and 11 at the same time that the slots such as 5 and 6 areformed therein. These perforations are so located with respect to theslots that when the bank is assembled and the conductors in place oneedge of each conductor is exposed. The sets ofmovable conductors 12, 13,14: 15 are arranged with their tips projecting through the perforationsin the bank and through the guide card 16, which is also of insulationand provided with angular slots. The rod 17 also extends through anaperture in the bank 10,.butis firmly fastened to the guide card so thatupon movement of said rod, the card will be elevated and the movableconductors brought into. contact with the fixed conductors 18, 19, 20,21 with a transverse rubbing motion. The operation of this type ofswitch is set forth in detail in the above identified Patent 1,507,140to J. N. Reynolds.

The modification of the invention shown in Fig. 5 differs from that ofFig. 2 only in having the conductors in the form of strips instead ofwires. Two sheets of insulation 22, 23 are slotted and corrugated in amanner similar to sheet 1 as shown in Fig. 3. The strips of metal 24project on both sides of the panel when formed and serve as contacts onbot-h sides thereof. A particular advantage of this type of panel is itsstrength, the mounting of the contact strips perpendioular to the bankserving to strengthen the bank transversely as well as horizontally.Another method of forming this latter type of bank, might consist incombining the corrugating slotting and assembly operations. In carryingout this method a pair of toothed drums are used for corrugating thesheets of insulation provided with circumferential grooves at thedesired intervals. The contact strips are fed through the grooves andthe sheets of insulation-are fed between the drums on either side of thestrips. As the sheets and strips progress through the drums the edges ofthe strips shear into the corrugations formed in the strips resulting intheir embedding themselves between the sheets. The assembled sheets andstrips are then passed between heated drums and subjected thereby topressure and heat.

What is claimed is:

1. A terminal bank comp-rising aplurality of corrugated sheets ofinsulating material, a

plurality of parallelly disposed conductors and means for supportingsaid conductors in spaced relation in said corrugations.

2. A terminal bank comprising corrugated and laminated sheets ofinsulating material and a plurality of parallelly disposed conductorssupported in spaced relation in said corrugations.

3. A terminal bank comprising a plurality of corrugated sheets of fiberimpregnated with a phenol formaldehyde resin and a plurality ofparallelly disposed conductors supported in spaced relation in saidcorrugations.

4;. A terminal bank comprising a plurality of corrugated sheets of fiberimpregnated with a phenol formaldehyde resin and parallelly disposedstrips of metal supported in spaced relation in said corrugations.

5. A terminal bank comprising a'plurality of corrugated sheets of fiberimpregnated with a phenol formaldehyde resin and a plurality ofparallelly disposed strips of metal supported in spaced relation in saidcorrugations with their faces perpendicular to the faces of said sheets.7

6. A terminal bank comprising a plurality of spaced horizontalconductors and a plurality of sheets of insulating material coexstensive with said terminal bank and provided with slotted corrugationsin which said conductors are supported. I

7. A terminal bank comprising a plurality of corrugated sheets ofinsulating material, transverse slots in said corrugations andconductors supported in parallel spaced relation in said slots.

8. A terminal bank comprising a plurality of corrugated sheets of fiberimpregnatedwith a phenol formaldehyde resin, parallel transverse slotsin said corrugations and conductors supported in spaced relation in saidslots.

9. A terminal bank comprising a plurality of corrugated sheets of fiberimpregnated with a phenol formaldehyde resin, parallel transverse slotsin said corrugations, a plurality of fiat strips of metal engaging saidslots and supported thereby in spaced rela tion and with their facesperpendicular to the face of the bank. 1

10. A method of forming a terminal bank consisting in corrugating andslotting a plurality of sheets of insulating material, dis posing aplurality of conductors in parallel spaced relation to each other,disposing said sheets of insulating material with said conductorsengaging the slots of said sheets and compacting the whole by means ofheat and pressure.

11. A method of forming a terminal bank consisting in corrugating' andslotting a plurality of sheets of fiber impregnated with a phenolformaldehyde resin in a sem1.-cured-.

' tors in parallel spaced relation to each other,

disposing said sheets of impregnated fiber With said conductors engagingthe slots therein, compacting the Whole and curing the impregnatingresin.

12. A method of forming a terminal bank consisting in corrugating andslotting a plurality of sheets of fiber impregnated With a plasticinsulating compound, disposing a plurality of strips of metal inparallel 1 spaced relation to each other, arranging said impregnatedsheets With said strips engaging the slots in said sheets and curingsaid impregnated sheets together.

In Witness whereof, I hereunto subscribe 15 my name this 2 day ofFebruary, A. D., 1924. p

' EDGAR W. GENT.

